This invention relates to systems and methods for lens stack manufacturing. Particularly, a system and method for black coating a camera cube at wafer level.
Black coating within an optical lens system prevents undesirable light from interfering within the operation of the lens system. For example, black coating within the lens system prevents internal reflections and incident exterior (or other stray light) light from impinging on the optical sensor.
Currently the black coating on the outside surface of camera cubes (e.g. a lens stack) is deposited utilizing a process that requires (i) masking the aperture of each die independently, (ii) placing each die into a spaced grid one at a time for coating, and (iii) manually removing the masking one at a time.
For example, FIG. 1 depicts a prior art method 10 for black coating camera cubes and an associated visual diagram 100. For example, in step 1, a lens 104 is attached to a sensor 102. In step 2, a plurality of lens/sensor groups are placed in a carrier 106. In step 3, the lens locations of each lens 104 are masked with masking material 108. In step 4, black coating 110 is applied on the outer surface of the lens/sensor group and masking material 108. In step 5, the black coating layer 110 is laser trimmed (indicated by dashed lines 112) at the locations where black coating 110 is undesired. In step 6, masking layer 108 and undesired black coating layer 110 are manually removed from the lens/sensor groups. In step 7, each individual sensor/lens group is removed from carrier 106.
The current black coating process has many disadvantages. For example, the manual process required to create individual lens/sensor groups, place the groups in the carrier, and manually remove the masking and black coating layer is slow and labor intensive.